问Element-ui NavMenu 导航菜单折叠，菜单名不隐藏，怎么在移除div的情况下达到效果？

<template>
  <div style="width: 300px;">
    <el-menu
      class="el-menu"
      :default-active="defaultActiveMenu"
      :collapse="isCollapse"
      background-color="#323743"
      text-color="#fff"
      active-text-color="#02c1de"
    >
      <span :class="defaultIconFoldClass" class="foldSpanClass" @click="foldClick"></span>

      <div>
        <el-menu-item index="1">
          <i class="el-icon-menu"></i>
          <span slot="title">导航一</span>
        </el-menu-item>
        <el-submenu index="2">
          <template slot="title">
            <i class="el-icon-location"></i>
            <span slot="title">导航二</span>
          </template>
          <el-menu-item index="2-1">选项1</el-menu-item>
          <el-menu-item index="2-2">选项2</el-menu-item>
        </el-submenu>
      </div>
    </el-menu>
  </div>
</template>